It is superior (in one sense) - it gives capabilities lacking in lower IQ people but it comes with metabolic and development time costs so you only get as much of it as can be translated into more surviving grandchildren. Same with any capacity like breath holding ability.
IOW you can't always get the theoretical max return for cost - you get a distribution of returns with a constant cost It still picks a point where the cost / benefit tradeoff is optimal then gets a randomly distributed payoff around that point